The single-domain globin from the pathogenic bacterium Campylobacter jejuni: novel D-helix conformation, proximal hydrogen bonding that influences ligand binding, and peroxidase-like redox properties.

ABSTRACT: The food-borne pathogen Campylobacter jejuni possesses a single-domain globin (Cgb) whose role in detoxifying nitric oxide has been unequivocally demonstrated through genetic and molecular approaches. The x-ray structure of cyanide-bound Cgb has been solved to a resolution of 1.35 A. The overall fold is a classic three-on-three alpha-helical globin fold, similar to that of myoglobin and Vgb from Vitreoscilla stercoraria. However, the D region (defined according to the standard globin fold nomenclature) of Cgb adopts a highly ordered alpha-helical conformation unlike any previously characterized members of this globin family, and the GlnE7 residue has an unexpected role in modulating the interaction between the ligand and the TyrB10 residue. The proximal hydrogen bonding network in Cgb demo

SUBMITTER: Shepherd M 

PROVIDER: S-EPMC2857070 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature